Thousands of activists are facing arrest this week and next at the White House to challenge President Obama to stop the Keystone XL tar sands pipeline. In addition to the devastating consequences to our climate if the carbon locked in the bituminous sands of Alberta is burned, the proposed pipeline also poses major contamination risks to the states on its path from Montana to Texas. The Keystone XL pipeline company TransCanada has a terrible pipeline spill record, but the management believes that the new pipeline will be the safest in history. Their confidence may be based on the foolhardy idea that threats you ignore won’t happen, Greenwire reports.

The Keystone XL pipeline will be carrying millions of barrels of diluted bitumen (dilbit) over thousands of miles, but the industry doesn’t actually know whether the pipeline can safely handle dilbit. Questions raised by environmental organizations like the Natural Resource Defense Council about the corrosion risk of dilbit have been dismissed by tar sands proponents as “emotion” with “no factual basis”:

“The challenge we have is combating emotion with facts,” said Alberta Energy Minister Ron Liepert during an interview this month when asked about the safety charges leveled by critics of oil sands development, particularly the $7 billion Keystone XL pipeline.

Liepert readily acknowledged, however, that few if any targeted studies of diluted bitumen’s corrosion risks are available to help him make the case for more oil sands development. . . .

The safety of shipping dilbit is simply “the latest issue that’s been raised by opponents to create doubt and uncertainty with no factual basis for it,” TransCanada CEO Russ Girling said during an interview this month in his Calgary office. Any corrosion risks already are managed effectively, he added, and they come “not from inside the pipe, but from the outside.”

Alberta’s Energy Resources Conservation Board chairman Dan McFadyen agreed. “If you look at systemic issues the pipeline industry has faced over the last several years, internal corrosion is not a factor,” he said.

Veteran pipeline engineer Richard Kuprewicz, a member of PHMSA’s safety advisory panel who has worked for both TransCanada and NRDC, offered a different take.

“Both external and internal corrosion are a factor” in pipeline failures, said Kuprewicz, president of the consulting firm AccuFacts, and the state of current regulations governing the latter is “a little weak.”

“There is no evidence from our tracking,” McFadyen told Greenwire, “that the type of product being carried in the pipeline results in anything different with respect to failure.”

But there’s “no evidence” only because the industry hasn’t actually bothered to study it. NRDC independently pulled together pipeline data and found that on dilbit pipelines, “corrosion abnormalities are occurring faster than [companies] are able to correct them.”